The method for producing phenol by hydrolyzing monochlorobenzene is known (for example, refer to U.S. Pat. No. 3,221,063 and U.S. Pat. No. 3,984,484).
Although the hydrolysis reaction mixture contains unreacted water, unreacted monochlorobenzene, phenol and hydrogen chloride, in order to separate phenol from the hydrolysis reaction mixture, it is necessary to remove water from the hydrolysis reaction mixture.
The above-mentioned known documents disclose a method in which water, hydrogen chloride and phenol in a hydrolysis reaction mixture are condensed and liquefied so as to be separated into a water phase mainly comprising water and hydrogen chloride and an oil phase mainly comprising phenol and monochlorobenzene, and the oil phase is further distilled to separate and collect phenol. However, this method has problems; water and hydrogen chloride are slightly dissolved in the separated oil phase, whereby the operation that is carried out when the oil phase is further distilled becomes complicated, and the selection range of materials of apparatuses for use in a distillation tower or the like is limited in view of corrosion prevention.